It's not about flipping. The two concepts are actually commutative. You could in theory create syntax that looks like this:

  FROMCLAUSE * SELECTCLAUSE * WHERECLAUSE = SQLEXPRESSION
  SELECTCLAUSE * WHERECLAUSE * FROMCLAUSE = SQLEXPRESSION
  ...

The issue is that not only does SQL syntax force an artificial order on these clauses, but that these clauses Cannot be decomposed to be used elsewhere. I cannot reuse a WHERECLAUSE or a SELECTCLAUSE in another expression.